208 research outputs found
Assessing forest availability for wood supply in Europe
The quantification of forests available for wood supply (FAWS) is essential for decision-making with regard to
the maintenance and enhancement of forest resources and their contribution to the global carbon cycle. The
provision of harmonized forest statistics is necessary for the development of forest associated policies and to
support decision-making. Based on the National Forest Inventory (NFI) data from 13 European countries, we
quantify and compare the areas and aboveground dry biomass (AGB) of FAWS and forest not available for wood
supply (FNAWS) according to national and reference definitions by determining the restrictions and associated
thresholds considered at country level to classify forests as FAWS or FNAWS.
FAWS represent between 75 and 95 % of forest area and AGB for most of the countries in this study. Economic
restrictions are the main factor limiting the availability of forests for wood supply, accounting for 67 % of the
total FNAWS area and 56 % of the total FNAWS AGB, followed by environmental restrictions. Profitability, slope
and accessibility as economic restrictions, and protected areas as environmental restrictions are the factors most
frequently considered to distinguish between FAWS and FNAWS. With respect to the area of FNAWS associated
with each type of restriction, an overlap among the restrictions of 13.7 % was identified. For most countries, the differences in the FNAWS areas and AGB estimates between national and reference definitions ranged from 0 to
5 %. These results highlight the applicability and reliability of a FAWS reference definition for most of the
European countries studied, thereby facilitating a consistent approach to assess forests available for supply for
the purpose of international reportinginfo:eu-repo/semantics/publishedVersio
Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments
Background: The tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes evaluating the dilution effect hypothesis and its influence across various scales challenging. Latitude, macroclimate, landscape and habitat properties drive both hosts and ticks and are comparable metrics across Europe. Therefore, we instead assess these environmental drivers as indicators and determine their respective roles for the prevalence of B. burgdorferi in I. ricinus. Methods: We sampled I. ricinus and measured environmental properties of macroclimate, landscape and habitat quality of forest patches in agricultural landscapes along a European macroclimatic gradient. We used linear mixed models to determine significant drivers and their relative importance for nymphal and adult B. burgdorferi prevalence. We suggest a new prevalence index, which is pool-size independent. Results: During summer months, our prevalence index varied between 0 and 0.4 per forest patch, indicating a low to moderate disservice. Habitat properties exerted a fourfold larger influence on B. burgdorferi prevalence than macroclimate and landscape properties combined. Increasingly available ecotone habitat of focal forest patches diluted and edge density at landscape scale amplified B. burgdorferi prevalence. Indicators of habitat attractiveness for tick hosts (food resources and shelter) were the most important predictors within habitat patches. More diverse and abundant macro- and microhabitat had a diluting effect, as it presumably diversifies the niches for tick-hosts and decreases the probability of contact between ticks and their hosts and hence the transmission likelihood.[br/] Conclusions: Diluting effects of more diverse habitat patches would pose another reason to maintain or restore high biodiversity in forest patches of rural landscapes. We suggest classifying habitat patches by their regulating services as dilution and amplification habitat, which predominantly either decrease or increase B. burgdorferi prevalence at local and landscape scale and hence LB risk. Particular emphasis on promoting LB-diluting properties should be put on the management of those habitats that are frequently used by humans. In the light of these findings, climate change may be of little concern for LB risk at local scales, but this should be evaluated further
Strength of forest edge effects on litter-dwelling macro-arthropods across Europe is influenced by forest age and edge properties
International audienceAim: Forests are highly fragmented across Western Europe, making forest edges im ‐portant features in many agricultural landscapes. Forest edges are subject to strong abiotic gradients altering the forest environment and resulting in strong biotic gradi ‐ents. This has the potential to change the forest's capacity to provide multiple eco ‐system services such as nutrient cycling, carbon sequestration and natural pest control. Soil organisms play a key role in this perspective; however, these taxa are rarely considered in forest edge research.Location: A latitudinal gradient of 2,000 km across Western Europe.Methods: We sampled six dominant taxa of litter‐dwelling macro‐arthropods (car ‐abid beetles, spiders, harvestmen, centipedes, millipedes and woodlice) in forest edges and interiors of 192 forest fragments in 12 agricultural landscapes. We related their abundance and community composition to distance from the edge and the inter ‐action with forest age, edge orientation and edge contrast (contrast between land use types at either side of the edge).Results: Three out of six macro‐arthropod taxa have higher activity‐density in forest edges compared to forest interiors. The abundance patterns along forest edge‐to‐in‐terior gradients interacted with forest age. Forest age and edge orientation also influ ‐enced within‐fragment compositional variation along the forest edge‐to‐interior gradient. Edge contrast influenced abundance gradients of generalist predators. In general, older forest fragments, south‐oriented edges and edges along structurally more continuous land use (lower contrast between forest and adjacent land use) re ‐sulted in stronger edge‐to‐interior gradients while recent forests, north‐oriented edges and sharp land use edges induced similarity between forest edge and interior along the forest edge‐to‐interior gradients in terms of species activity‐density and composition.Main conclusions: Edge effects on litter‐dwelling macro‐arthropods are anticipated to feedback on important ecosystem services such as nutrient cycling, carbon se ‐questration and natural pest control from small forest fragments
Bryophytes collected during the 12th “Iter Mediterraneum” (Tunisia, 24 March – 4 April, 2014). First contribution
Part of the bryophytes collected during Iter Mediterraneum XII is listed. Some noteworthy
species were found: Dicranella howei, had so far been recorded only doubtfully from
Tunisia; Funaria hygrometrica, Grimmia laevigata, Grimmia trichophylla, Imbribryum
alpinum, Pogonatum nanum, Rhynchostegium riparioides, Scleropodium touretii,
Scorpiurium circinatum, Thamnobryum alopecurum, Timmiella barbuloides, Tortella
squarrosa, Tortula muralis and Tortula vahliana, had not been reported from that country
for more than half a century
Premium Price Pengelolaan Sumberdaya Hutan Produksi Bersertifikasi
Forest certification is a key issue in relation to the forest products industry. It's also a new trend market of forest products. Forest certification is a guarantee that the products resulting from the forest management process in accordance with the standard of sustainable forest resources management. Certification will be increasing the cost of management as an impact of fulfilling requirement on the criteria of the certified forest. The fundamental question whether the award of certified products has been accompanied by an increase in premium price for forest estate or only becoming as the cost that reducing profit for the forest estate. The aims of this research are: 1) to know the difference between the sales price of certified and non-certified wood, 2) to know the premium price on certified forests, 3) to identify the factors that influence the amount of premium price of the certified forest. Data collection were used by searching the document and literature reference on forest certification. The results showed that the premium price received from the certified timber is higher than non-certified timber. Certified wood with high quality has a premium price that is greater than the low-quality wood. The percentage of premium price received varied forest estate. Premium price sometimes unsignificantly received by small-scale of timber estate. The revenue of premium price of certifies forest is influenced by the following factors: 1) The forest area to be certified, 2) Organizations that perform assessments, 3) Company / bodies / organizations that filed the certification, 4) he The country as a buyer of certified timber product 5) the facilitator in the market activities, 6) post-certification fee, and 7) the sales price
Endangered Plants in Novel Urban Ecosystems Are Filtered by Strategy Type and Dispersal Syndrome, Not by Spatial Dependence on Natural Remnants
Understanding the contribution of cities to nature conservation is gaining increasing importance with a globally accelerating urbanization and requires insights into the mechanisms that underlie urban distribution patterns. While a considerable number of endangered plant species have been reported for cities, the spatial dependence of populations of these species on natural remnants versus anthropogenic ecosystems is critically understudied due to deficiencies in population distribution data. To which extent endangered species in anthropogenic ecosystems spatially rely on natural remnants is thus an open question. We used a unique dataset of 1,742 precisely mapped populations of 213 endangered plant species in the city of Berlin and related these point data to habitat patches that had been assigned to natural remnants, hybrid ecosystems and novel ecosystems according to the novel ecosystem approach. By applying point pattern analyses (Ripley’s K function, cross K function, cross pair correlation function) we unraveled the spatial dependence of the populations toward the different ecosystem types. Moreover, we tested how plant traits related to plant strategy and dispersal filter for species occurrence across ecosystems. Differentiating populations on anthropogenic sites revealed that populations in hybrid ecosystems spatially depended on natural remnants, but populations in novel ecosystems (i.e. more than a third of all populations) surprisingly didn’t. A conditional inference tree showed that endangered plant species in novel ecosystems are filtered for ruderal strategy type and wind dispersal syndrome, while competitive and stress-tolerant species were mainly confined to natural remnants. Our results highlight the importance of conserving natural remnants as habitats and seed sources of endangered plants. Yet novel urban ecosystems can support many populations of endangered plant species beyond the adjacency to natural remnants, with hybrid ecosystems likely acting as stepping stones. This indicates a specific contribution of urban ecosystems to biodiversity conservation. Since different filters modulate the species pools of different ecosystem types, novel urban ecosystems are not supposed to substitute fully the habitat functions of natural remnants. Our study thus highlights promising opportunities for involving the total range of urban ecosystem types into urban conservation approaches.DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität BerlinBMBF, 01LC1501, BIBS-Verbund: Bridging in Biodiversity Science (BIBS
An Overview of Modelling Bulgarian Wildland Fire Behaviour by Application of a Mathematical Game Method and WRF-Fire Models
This paper presents the main achievements of the author’s PhD dissertation.
The work is dedicated to mathematical and semi-empirical approaches applied to
the case of Bulgarian wildland fires. After the introductory explanations,
short information from every chapter is extracted to cover the main
parts of the obtained results. The methods used are described in
brief and main outcomes are listed. ACM Computing Classification System (1998): D.1.3, D.2.0, K.5.1
Seasonal changes in host phenotype manipulation by an acanthocephalan: time to be transmitted?
Many complex life cycle parasites exhibit seasonal transmission between hosts. Expression of parasite traits related to transmission, such as the manipulation of host phenotype, may peak in seasons when transmission is optimal. The acanthocephalan Acanthocephalus lucii is primarily transmitted to its fish definitive host in spring. We assessed whether the parasitic alteration of 2 traits (hiding behaviour and coloration) in the isopod intermediate host was more pronounced at this time of year. Refuge use by infected isopods was lower, relative to uninfected isopods, in spring than in summer or fall. Infected isopods had darker abdomens than uninfected isopods, but this difference did not vary between seasons. The level of host alteration was unaffected by exposing isopods to different light and temperature regimes. In a group of infected isopods kept at 4°C, refuge use decreased from November to May, indicating that reduced hiding in spring develops during winter. Keeping isopods at 16°C instead of 4°C resulted in higher mortality but not accelerated changes in host behaviour. Our results suggest that changes in host and/or parasite age, not environmental conditions, underlie the seasonal alteration of host behaviour, but further work is necessary to determine if this is an adaptive parasite strategy to be transmitted in a particular seaso
Potential shift in tree species composition after interaction of fire and drought in the Central Alps
The future trajectory of forest ecosystems under climate change is heavily debated. Previous studies on the impacts of climate change on forest ecosystems have focused mainly on direct effects of altered climatic conditions, whereas interactions with disturbance events have been largely neglected. The aim of this study is to explore interactions of drought with fire disturbance and to assess their effects on tree species shifts in the European Central Alps. Tree recruitment after a stand replacing wildfire in the Rhone valley, Switzerland, was measured along an altitudinal temperature moisture gradient. Recruitment was more successful in pioneer species (Betula pendula, Populus tremula and Salix appendiculata) than in pre-fire stand forming (PFSF) species (Larix decidua, Picea abies and Pinus sylvestris). Seedling and sapling density was not related to fire intensity, but it correlated with the distance to the forest edge in PFSF species. The window of opportunity for seedling establishment was short (1-2years), and moisture deficit was the main limiting factor for tree recruitment at lower altitudes. We suggest that prolonged drought periods, as projected under continued global warming, will further aggravate tree recruitment success after fire disturbance at low altitudes of the Central Alps and may eventually lead to a shift from PFSF species to either more drought-tolerant species or to forest-free vegetatio
Adapting a growth equation to model tree regeneration in mountain forests
Management and risk analysis of protection forests depend on a reliable estimation of regeneration processes and tree growth under different site conditions. While the growth of forest stands and thus the average growth of larger trees is well studied and published in yield tables as well as embodied in numerous simulation models, there is still a lack of information about the crucial initial stages of tree growth. Thus, we evaluated juvenile tree growth for different site conditions in the Swiss Alps and developed an approach to model both the early and later stages of growth based on the Bertalanffy equation. This equation is physiologically well founded and requires only two parameter estimates: a maximum tree height and a growth parameter. Data for the parameter estimation were available from studies of tree regeneration at a range of sites in Switzerland: growth patterns of larch (Larix decidua) were available from a high-elevation afforestation experiment. For spruce (Picea abies), data were obtained from a blowdown area in the Alps. The growth equation was fitted to the observed data and we found a good correlation of the fitted curves with the observed data. The parameter estimates were validated with independent data sets. The extrapolated growth curves, calculated with the estimated growth rates, correspond well to the validation data. Thus, it is possible to use the Bertalanffy equation to model both the early and later stages of growth. With this approach, we provide a basis for modelling the growth of juvenile and mature trees of different tree species in mountain forests of the European Alp
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